Greetings. I'm thinking about replacing my 4700's outer chainring (Tiagra 4700 110mm 50-34T 10spd) - it appears to be pretty beat up after just 4000km...surprisingly - and I found a slightly cheaper 105 version.

(1) So I'm curious, can the 105 FC-5800 110mm 50-34T 11spd be used instead... and is there really a difference when it comes to outer rings in terms 10 vs 11 speed (given the other specs are the same)? I'm still in the learning stage, as you can tell.

(2) Another option is to go with 4700 52-36T instead. Any thoughts on this vs. the 50-34T?

(3) And my last question... in the back, I have the Shimano HG500 11-34 10s cassette. Would this be compatible with any of the above-mentioned variations? (Does it matter, in general, which crankset it's paired up with?).

Cheers!

It would be almost impossible to wear out an outer chainring in only 4000 km. I have ridden 10 times as far as that before one wore out

Either that or I've stretched my chain out..due to some bad crosschaining habits (live and learn), as there's a bit of play in the "pinch test."
I'll post some pictures once I hit my "10 Post Milestone." The inner chainring looks pristine, but the teeth outer quite rough and uneven...

Are you referring to the "cut outs" spaced somewhat equally around the ring to aid in shifting?

It is entirely possible to wear a chain out in 4000 km. Those "rough and uneven" teeth on the large chainring are made that way to aid shifting

Why wait for ten posts? Just write the URL of your pic in the plain text of your message. Remove the https:// and change the "." to " dot ". If the spam filters still balk, then do some further obfuscation. We'll figure out how to make the link work. For some pic hosting sites you might need to use the URL that you get from the share function of that site. You might be able to upload to BF's gallery if you need a hosting site, though I don't know the policy for newbs.

But yes modern chain rings have a lot of shaping and sculpting on the teeth. Many teeth looking entirely different from the one next to it.

And also, even if you have damaged some teeth and they look chewed up.... are they giving you any problems? If not, don't be in a hurry to change them. Might be better to learn what in your shifting technique is causing them to get chewed up and correct that first. Then perfect that by riding another 2 or 3 thousand miles or more before summer gets here.

No sense changing something that currently works.

Measure your chain with a ruler to accurately determine chain "stretch". https://www.sheldonbrown.com/chain-wear.html#measure
As to the uneven teeth, I think that you will find the "uneven" teeth are periodically arranged around the chainring and are associated with the shift pins and ramps.

Thanks for the tips, I'll give it a go this weekend.

Good call! here's some stuff I've shot earlier:



Chainring:
w.. [dot] streamable [dot] c o m /ndl2d2

Chain:
w.. [dot] streamable [dot] c o m /65r0oi

images:

w.. [dot] ibb [dot] c o /2hjyrgF

w.. [dot] ibb [dot] c o /st05Xqh

https://streamable.com/ndl2d2

https://streamable.com//65r0oi

https://ibb.co/2hjyrgF

https://ibb.co/st05Xqh

I got a new bike in March with Ultegra on it. After a few hundred miles, I was thinking the teeth look a little chewed up too even though I've been very aware of the shaping and sculpting they do on the individual teeth. It actually did look a little chewed up. Might have been me getting used to the speed at which the Di2 shifted and coordinating when I eased up a bit on the power. Certainly never noticed such on my previous 105 5800 equipped bike.

However I didn't worry... at least not much... and continued to ride the bike since it wasn't causing any issues. I did do some tweaking of adjustments, but that was more for noise and getting the Di2 lined up better with the sprockets.

Over 2000 miles (3218.7 km) later, it's still not an issue. The teeth don't look any worse and it shifts great.

One vid showed you pulling the chain to show slack while on the chain wheel. All I can say to that is measure your chain. A steel tape or metal scale works best for me. Just see how 12 inches compares to 12 links. If that 12th link is more than a 1/16th" beyond the 12" mark, then it's about time to replace the chain. If you are metric, then use 10 links and 254 mm, if beyond 255 mm then it's time to start thinking about it.

I keep a little tension on my chain with the crank and the rear on the ground or brake set. Then measure from left side of a pin to the same side of the pin near the 12" mark. https://road.cc/content/feature/when...-219450?page=1

11 speed and up, most say replace if 1/16" or 1 mm longer, roughly .5%. For 10 speed and lower some say you can wait till .75%. However it's up to you. I've had chains go twice that when I wasn't checking regularly and not had issues with new chain on cogs, but other times I have had issues.

I truly appreciate your help and input, Iride01 (and the rest)! Time to do some math.